Sewing-machine.



W. V. MILLER.

SEWING MACHINE.

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W. V. MILLER.

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Imran/t0n W. Y. MILLER.

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UNITED STATES PTENT OFFICE.

WILLIAM V. KILLER, OF TORONTO, ONTARIO, CANADA., ASSIGNOR, BY HESNE ASSIGN- MENTS, TO THE SINGER HANUFACTURING COMPANY, OF NEW YORK, N. Y., A

CORPORATION OF NEW JERSEY.

SEWING-MACHINE.

Specification ot Letters Patent.

To all whom 'it may concern:

Be it known that I, WmLmM Vnnn'rrn MILLER, a citizen of the United States, and resident of Toronto, in the county of York and Province of Ontario, Canada, have invented certain new and useful Im rovements in Se -Machines; and Ihere y declare that the ollowing is a full, clear, and exact descriptionof the same.

This invention 'relates to certain new and useful improvements in that class of sewing machine employed for button sewing, tack ing, staying, and French knot mak' purposes, and it relates more particular y; 1. To an upper-thread-retainer attached to the needle bar, operable means to actuate the upper-thread-retainer to clamp the upper thread and prevent its withdrawal from the needle eye, and other means to automatically actuate the upper-thread-retainer to release the up r-thread on the completion of the first stitch of each sewing operation; 2. To an up rthread-clamp and means to automatica y actnate it to engage the upperthread previous to or coincident with the release of the u per-thread-retainer, and securely hold it dhr-ing the formation oi the first stitch and any selected number of stitches thereafter, and then automatically actuate it to release the upper-thread so that its end may be sewn into, and prevented from appearing above or below the surface of the work 3. To a threadseveringmecha nism located below the work-holding-clamp, means to automatically position it where the upper-thread-seve -members will enter the loop of the last stitch, of each sewing operation, during the formation thereof, operable means to actuate the thread-severing members when positioned within said loop to successively sever the upper and the bobbin threads preferahl previous to the release of the work-hol ing-clamp; and 4. To a bobbin-thread-clamp to securely hold the bobbin thread, for the formation of the first stitch of each sewing o ration.

For a full understan 'ng of the invent-ion reference is to be had to the followin descriptien and to the accompanying rawn in which,

ugure 1 is a side elevation of a sewing machine, showmgthe constructive arrangement of the paris; Fig. 2 is a front elevation of the same. F ig. 3 is a plan view of the under side of the sewing machine showing the first nud fourth positions of the operating mechanism for positioning the threadsevering-mechanism. Fig. 3 is a similar view to Fig. 3, showing the second posit-ion. and Fig. 3" is n similar vien-r to Fig. 3, show-l ing the third position of the operating mechanism. Fig. -1 is a. side elevation of the operable means for actuating the oscillating members of the thread-severinU-lnechanism. Fig. 5 is a plan view showimY the first or extreme advance position of t 1e thread-severing-mechanism or the posit-ion of the parts preparatory to the downward movement of the needle bar for the first stitch; this being also the fourth position of the thread-severing-mechanism or the position of the parte during the formation of the last stitch of the sewing operation. Fig. 6 is a similar View to Fig. 5, showing the thread-Severin -members actuated to sever the upper and obbin threads. Fig. 7 is a plan View showing the second or intermediate position of the thread-severing-n'lechanism, this being the position into which the thread-severingmechunism moves during the upward movement of the needle bar for the first stitch, and the position in which the tl'uead-severing-mechanism is detained during the formation of any selected number of stitches thereafter. Fig. 8 is a plan view showing the third or extreme retracted )osition of the thread-severing-mechanism. 9 is a plan view with the slide-plate and related parts removed to show the location of the lowerthread severing-blade when'lhe parts are in tho position .shown in Fig. Fig. 1() is a Similar View to Fig. 9, to show the location of theI lower-threada severing-blade when the parte are in the position shown in Fig. 6. ig. 1l is a similar view to Figs. 9 and 10 to show the location of the lower-thread sovering-blade when the parts are in the position shown iu Fig. 7. lig. 12 is a plan view lo show the upper-thread-clamp in its inoperative position. Fig. 13 is n similar view to F ig. 12, to show the upper-threudclnmp in its operative position. Fig. 1l is a section on the lines a-a Fig. 12. Fig. 15 is u plan View of the workholding-clamp. Fig. 16 is a longitudinal section on the lines af-a Fig. 15. Fig. 17 is a plan view of the work- Patented Oct. 18, 1910.

V.-flloldil,lg-Jaws detached from the related parts.

' `ig. 18 is a perspective view of the swinging arm for actuating the upperthrcxuL'retainer. Fi, 19 is a perspective view of the upper-tliread-retaiuer in its .inoperative position. Fig. .20 is a erspectrve view of tie uJper-threadretainer in its operative position. Fig. 2l is a'sectlonal view on the lines u-a Fig. 19. Fig. 22 1s a sectional view on the lines a-ri Fig. 20. Fig. is a sectional view taken at right angles to Fig. 2l. Fig. 2l a perspectlve view of that part of the needle-bar contalned in the upper-thread-clamp, and Fig. 25 is a front elevation of the loop-taker and threadsevering-mechanism.

Like letters of reference refer to like parts throughout the specification and draw- 01- the purpose of explaining the construction, operation and purpose of the novel features of the invention they have been shown and described in connection with certain other features of a sewing machine, but as they can be used in connection with'a sewing machine of other makes it is not intended that their use should be confined to the particular machine shown and 'described in the present application, nor 1s it necessary to describe in detail the construction or operation of an;v of the parts of the sewin machine except such as are direct-ly relater to the present invention.

The upperkreadretuinen-Before start ing the operation of the machine, the needle a is threaded and the projecting part of the upper thread b is cut to the required length preferably the length of the needle so as to correspond to the distance between the needle eye c and the upperthread-clamp (I, and the up er-thread-retainer is then set to preventt e. withdrawal of the upper thread from the needle eye.

The upper-thread-ret-ainer consists of an annular sleeve p mounted on the needle bar g near the lower end of the latter, and is slightly greater in diameter than the encircled part. of the needle bar. so that. it will not cut or bruise the upper thread when clamped between the wal of the sleeve and the surface of the needle bar. Formed in the needle bar q is a thread groove r and formed in the annular sleeve 71 is a thread aperture .sito register with the thread-groove r when the upper-thread-retainer is set in its inoperative position.

To thread the needle, the annular sleeve is sett so that the thread aperture s will register with the thread groove r. and the upper thread is t-hen conducted from the threadtake-up t through the thread aperture and thread roove to the needle eye c. When the neetlle is threaded the annular sleeve is moved intoa aperture s will osition in which the thread "at of line with the thread groove-1' so that the wall of the annular sleeve p can clam the thread between itself and the surface o the needle-bar, the clamping part of the wall of the annular .sleeve being yieldingl)r held against. the corresponding part of the needlebar by a spring p* interposed between the wall of the sleeve and a socket in the needle bar diametrically opposite the thread-clamping-parts. Pro- 'ecting from the outer surface of the annuar sleeve pis a wing m, and opposed to the wing m is a. reciprocating arm Z attached to or forming part of the swinging-ann j pivotally connected with the lower bearing l: for the slide-bar g. The swinging-arm j hangs from the bearing k contiguous to the slide-bar g and formed in the swinging-arm is a skeleton cam i in which travels a stud h projecting from the adjacent surface of the slide-bar. The slide-bar g is raised by a lifting lever f rockable on a fulcrum p2 projecting from the horizontal arm 3 ofthe main frame, and is lowered when t e lifting lever is released, by the usual tension spring 90 At te completion of each group of stitches, the machine is stop d with the take-up lever t in substantalliya its highest position, at which time the needle is in the initial portion of its downward movement, with the lateral wing m of the loose sleevep just below the fixed cam member u and at le level of the arm Z of the swinging mem- When the needle is threaded the lifting lever is actuated to raise the spring tension slide bar g. During the upward movement of the slide-bar the stud h travels in the skeleton cam z' and causes the forward movement of the swinging arm j to bring the reciprocating arm l into engagement with the wing fm, and rotate the annular sleeve p on the needle bar g. The rot-ation of the annular sleeve on the needle-bar moves the thread aperture s out. of line with the thread groove r so that the wall of the annular sleeve p will clamp the thread between itself and the needle bar and prevent the thread-take-up t withdrawing the upper thread from the needle eye while the U5 needle bar moves downwardly or upwardl)T for the formation of the first stitch. Then the appel-threznl-retainer is set to clamp the upper thread the lifting lever is released and the slide bar g is lowered by the ten- 120 sion sprin 'i'. During the descent of the slide-bar the stud li travels downwardly in the skeleton cam i and moves the swinging arm and the reciprocating arm l rearward y and out of engagement. with the upper-threadafetainer set in its` operative position.

As the needle-bar nears the completion of its ascending movcn'lent, the wlng fm. 1s engaged by the releasing cam u attached to the lower hearing o for the needle-bar and this cam as the needle-bar completes its ascending movement automatically restores the wing m and annular sleeve p to the1r normal positions to release the upper thread and cause the thread aperture s to aime wlth the thread Groove 7' so that the thread there after may ii'eelv pass from the threadtakeup to the needle eye during the conti11u ed movement of the needle bar. During the descent of the needle har, the needle carries the upper thread through the needle aperture v in the throatplate 1e and as the needle bar ascends the bea-k m of the loop-taker, herein represented of the rotating shuttle type, enga es the upper thread and draws lts free end beneath the throat plate u.' to be engaged by the upper-thread-clamp (l.

The upper'-tLrefuLcZampf-Irevions to, or (ro-incident with the release of the upperthread-retainer, the u pper-threadclam p d is actuated to endage the end of the upper thread and hold it for any selected number of stitches, to nevent the. withdrawal of the upper thread through the Work, and is again actuated on the completion of the selected number of stitches to release the upper thread so that. its end can be sewn into the work.

In the under side of the throat plate is an annular counter sunk recess located vertically below the needle. bar and extending through the throatplate within the circumference of the annular recess is the needle aperture 'L'. see Figs. 5 to 13 inclusive. The upper-thread-clam i d is centrally contained m the counter sun recess z, and consists of a hub a.' and a series of fingers c projecting` radially from the hub, and of sutlicient length to move across the needle aperture 'v as the upper-thread-clamp revolves.

As shown in Figs. 12. 13 and 14. the thread-clamping part Z13 of the surface of the recess is located at the side of the needle aperture r and at the side of the threadclamping part b3 is a depression n3. The upper-thread-clam i f1. is revolved by a spring dog d carried v the slide plate e in the direction indicated by arrow in Figs. 12 and 13, and during its revolution the radial tingels c' successively move across the needle aperture to the thread-clamping part If. ln the slide plate c' are longitudinally disposed slots c2 and contained in the slots e are guide-blocks e3 of wellknown form to direct and limit the movement of the slide plate. Passing throutrh the block ez are screws n* which enter tlic throat plate to fasten the blocks thereto. The screws e* have washers c overlapping the edges of. the slots and engaging the under surface of the slide plate to slidubly connect the slide plate to the throat plate. The slide-plate. e derives its reciprocating movements crosswise of the bed-plate from a rotary calma-'heel driven by any wellknown or suitable means, and provided with a camroove h' entered by a stud at one end of a ever f', fulcrumed intermediate its ends upon a stud-screw f2 upon the under side of the base g' and having its opposite end connected by means of a link f3 with a screw-stud Z2 upon the slideplate e.

The slide plate e is in the position shown in Fig. 5 during the downward movement of the needle bar for the {irst stitch of each sewing operation, and as the needle bar ascends the slide late e' is moved by the roeking lever f ang face cam h from the position shown in Fig. 5, to that shown in Fig. 7. This movement of the slide plate causes the spring do d to engage one of the radial lingers c' an move the finger indicated by the reference numeral 2 across the needle aperture to engage the end of the upper-thread and clamp 1t between itself and the threadclampngpart b3. The face cam h' is formed to arrest the movement of the slide late and hold it in the position shown in ig. 7, for any selected number of stitches, so that when the spring dog has moved the radial finger e' across and clear of the needle a erture it will hold it opposite the threadc amping-part b3 to clamp the upper thread until the selected number of stitches has been completed. When the selected number of stitches has been eonipleted, the face cam.

h' again actuates the rockin lever to move the slide late into the position shown in Fig. 8, and canse the, spring dog d' to complete the motion of the radial linger o by moving it. opposite the depression 113 where it releases the upper thread so that the end may be sewn into and prevented from appearing above or below the surface of the work. The needle-bar then performs the predetermined number of stitches to complete the sewing operation, and during the formation of the last stitch of the sewing operation the face cam h' again actuates the rocking lever f' to move the slide plate from the position shown in Fig. 8, to that shown in Fig. 5, where the spring dog Il will engage one of the radial fingers f" to actuate the npper-thread-clamp during the first stitch of the next sewing operation. .\ttached to the throat plate wf is a friction spring z" projecting partly across the annular recess .z and in the path of the radial fingers c with which it engages during the rotation of the upper-thread-clamp to prevent more than one radial linger moving across. the needle aperture on each operation of the slide plate and to prevent retrograde movement of the upper-thread-clamp as the tudinally of and integral with operative upturned extremity of the springdog rises over the beveled edge of the previously engaged finger c in its return movement with the slide-plate from the position shown in Fig. 8 to that shown in Fig. 5.

The thread-scvering-meehansm.-ln the slide plate e' is a throat aperture j to register with the needle aperture o when the slide plate is in the position shown in Figs. and 7 to provide for the free movement of the needle during the operation of the needle bar. The slide-plate e is provided at the end adjacent the path of movement of the shuttle-beak with a throat-aperture 7" at one side of which and arranged longithe slideplate is a blade or finger k havinfr a sharpened operative knife-edge and forming what is herein termed For convenienceI the fixed severing member, which. While movable with the slide-plate at other times, is maintained in fixed or stationary position relative to the stitch-forming mechanism during the thread-severing operation. Fulcrumed to the under side of the slide-plate e' by means of a. screw-stud Z2 is the oscllla-ting or vibrating lever Z having at its operative end a blade or finger m/forming a movable upperA thread severing member, which preferably corresponds in sha-pe and' dimenslons with and underlies the xed severing member k. When the slide-plate is in the positions shown in Figs. 7 and 8, the movable blade m registers with the relatively fixed bla-de k and is locked in such relatlon therewith by means to be hereinafter described.

Fulcrumed to the under side of the throatplate w above the slide-plate e by means of the stationary screw-stud i2 is an oscillating or vibrating lever 1" having at its forward extremity an inclined cutting edge n forming a severing member for the lower-thread, this lever having a slot s to register with the guiding cam g in the adjacent face oi the throat plate and forming part of the gl-pidin cam q' is a keeper p. Formed t rou the slide late e is a. curved slot o5 to register with t e slots in the severing member r and with the guiding cam g' in the throat plate. Projecting from the upper face of the oscillating severing member l is a stud o which extends through slots 05 and s and enters the guiding cam q. When the slide late is in the position shown in Fig. 8, t xe stud 0 is contained in the kee er to prevent the movement of the oscillating severing members Z and -r so that there will be no possibility of the severing members moving accidentally or otherwise into the needle path. Inasmncli as the connecting stud o of the overlving levers l' and tr is disposed interme iat-e their respective fulcr-a. Z2 and f2, it is evi- 65 dent that the movement of the lever Z' upon its fulcruu'l-stud Z2 will produce by means of the stud o' und slot s u movement of the lever 'r' upon its fulcrum r2 in the opposite direction.

During the formation of the first stitch of cach sewing operation, the slide plate is actuated to move the severing members into the position shown in Fig. 5, in which position it maintained during the initial descent of the needle bar. It is then moved from the position shown in Fig. 5, to that shown in Fig. 7, in which position, it is held during the formation of any selected number of stitches. It is then moved into the posit-ion shown in Fig. 8, where it is maintained unt-il the connnencement of the formation of the last stitch of the sewing operation. During the formation of the last stitch= the face cam h actuates the rocking lever f to move the slide plate from the position shown in Fig. 8 to that shown in Fig. 5, so that the fixed Severin member k' and the blade m' of the oscillating severing member l will enter the needle-threadloop distended by the shuttle in the final stitch'- forming operation. This needlethread-loop is tightened around the fixed Severin member Ilz' and the blade of the oscillating severing member l by the needle bar and the thread-take-up as they complete their iinal movements.

The movement of the slide plate from the retracted position shown in Fig. 8, to the extreme advance position represented in Fig. 5, releases the stud o from the keeper 100 p', and `when released the oscillating severing members Z and -r can be actuated, by means now to be described, to successively sever the upper and bobbin threads respectively, as they move from the posit-ions 105 shown in Figs. 5 and 9, to those shown in Figs. 6 and 10.

'I he oscillating severing member l is connected b v a link t to a collar u innnovably fixed on the sliding bar v actuated by a 110 flexible connection 'w' from a pedal lever or other usual or well -known power source.

,onneetcd to the collar u and to the base g is a. tension spring e by which the collar is returned to its normal position when re- 115 leased from the influence of the actuating power. It is possible to employ a stationary guide bar 'u' and slidably mount on the guide bar a spring tensioned collar u' and connect that collar with the pedal lever (not 120 shown) for the same purpose.. and operate it iu the same way as above stated. Then the last stitch com pletcd and the motion of ilul needle bar has stopped, the pedal lever is actuated to operate the thread-severing-means. During the actuation of the )odell lever. the collar u moves the link I" 1n the direction indicated by arrow in Fig. 3. to move the oscillating severing member l' from the position shown in Fig. 5, to that 130 shown in Fig. 6, and strain the uplper thread againet the cutting ed e of the fixed severing member pon its arther side from the needle-pole and positively sever it. The strain of the threadloop by the action of the member m', as the term implies, involves the employment of a blunt edge of such member to engage the thread upon the side adjacent the needle-hole fv, and thisl is provided i n order that the tension imposed upon the tightened thread-loop by the movement of the member m. may serve to part the thread always at the same point and as close as possible to the oods. While the natural tendency of the evice would be to sever the thread at the edge of the tixed finger k farthest from the needle-hole o, the provision of a cutting edge at. such point increases materially the uniformity of ac tion of the severing device upon the thread. The oscillating severing member l' as it moves awav from the fixed severing member l." ennages the lower or shuttle-thread iutermeldiate the shuttle and the needle-hole and draws off sutlicient bobbin thread for the next sewing operation and carries it to the bobbin-thread-clamp located below the slide plate by which it. is held until the initial stitch of the nextV sewing operation, and cri-incident with the actuation of the oscillatini.; Severin member I', the oscillating severing mem er r' moves in the opposite direction toward the needle aperture v and when the bobbin thread is clamped by the bobbintl'n'ead-clam i, .':evers the bobbin thread above the slide plate. lfpon the rclease of the actuating means for the link 1". the link is restored to its initial position b v the action of the tension spring e, and as it returns to its initial position, it returns the oscillating severing members Z and i" from the positions shown in Figs. (i and l0 tot'hose shown in Figs. and 9 in which positions they and the slide )late remain while the needle bar descends for the first stitch of the next sewing operation.

The face cam li when it comes into the position shown in Fig. 3. actnatcs the rocking lever to move the slide plate into the po.:tion shown in Fig. which may be termed the first and fourth positions of the operating mechanism as the slide plate and related parte are in the position shown in Fig. 5, when the needle bar commences the downward movement for the first stitch of each sewing operation. and they are in the same position while the needle bar com )let-es the upward moven'ient of its filial stro 'e on the formation of the last stitch of each sewingr operation. From the position shown in Flg. 3, the face cam Il. moves into the position shown in Fig. f5, to move the slide plate from the position shown in Fig. to that shown in Fig. T, which ma;r be termed the second or intermediairl position of the operating parts as the slide plate is permitted to remain stationary in this position until the selected number of stitches have been completed. Froln the position shown in Fig. 3, the cam moves to the position shown in Fig. 3", which may be termed the third position of the operating mechanism, in which position the slide plate is held stationary until the remaining stitches have been completed. From the position shown in Fig. 3b, the cani moves to the )osit-ion shown in Fig. 3. to restore the sli e plate and related parts to the position shown in Fig. 5. This makes a complete revolution ot' the face cam and a complete series of operations of the slide plate.

The bobbzwthread-clamp. The bobbinthread-clamp y' is secured to the under side of the throat plate fw and is located in the path of the oscillating; severing member I' when positioned as shown in Figs. 5 and so that as the oscillating severing member s" moves away from the fixed severing member, it. wilLdraw ott sutlicient bobbin thread for'the initial stitch of the nextsewing o eration and carry it beneath the bobbin-threa -cla1np. The bobbin-thread-clamp consists of a s ring pressed arm y2 fastened to the throat p ate at the side of the slide plate and when the oscillatin severing member carries the bobbin threa to it, it clamps the bobbinthread between itself and the slide plate and securely holds the bobbin thread until it is withdrawn h v the operation of the stitch forming mechanism. The relation of these parts is such that when the blade lm. carries the under or bobbin thread between the clam ing member y and the slide-plate e', the tiread is Ripped with such force as to maintain taut the portion connected with Je. work after the chopping action of the severing member a. thereby effective] f prcventing the drawing olf from the bob in of more under thread than that. measured oi by the lever l'. Upon the withdrawal of the lever l' from beneath the spring-pressed clamping member y', t-he latter is permitted to approach the slide-plate e sufficiently to maintain a slight. pressure upon the severed bobbin thread, so as to retain it. temporarily, but to readily release itas soon as it is euaged by a loop of needle-thread in the ro- (gluct-ion of the first stitch of a succee ing series.

The 'work-wlflingwlam-p. The lifting lever f is preferably connected with the pedal lever by a liexible connecting member so adjusted as to canse the actuation of thc lifting level' subsequent. to the actuation of the thread-severiiig-mechanism, to cause the lifting lever to raise the work-holding-clam p for the removal of the work after the up er and bobbin threads have been severed. `he workholding-clamp consists of two worliholding-jaws a' and e', pivotally and inde- 4site sides of the medial line of the clamp V- late and on an ima inary line intersect-ing he medial line at right angles thereto, as

shown in dotted line in Fig. 15. Formed on the wm'k-holding-jaw s is a male spur tooth and formed on the work-holding jaw e2 is a female tooth d2 into which enters the male tooth c2. The center of the pitch line of these teeth is at the point of intersection of. the medial and imaginary lines above mentioned and from this center the work-holding-jaws open and close in unison. Normally pressing the work holding jaws together are tension springs f2 connected to the clamp plate z3 by a screw ge. Locking the work-holding-jaws in their closed position is a tapering locking pin h2 which passes through the cla-mp late .es between the work-holding-jaws 1n rear of their fulcrnm screws. Holding the tapering locking pin in position between the rear ends of the work-holding jaws is a spring tensioned locking bar h. Connecting the tapering locking pin with the lifting lever f is a link i2. Durin the actuation of the lift-in lever f, t e link raises the tape-ring ocking pin to release the work-holding-jaws, and to lift. the jaws from the work by the engagement of a shoulder j formed on the tapering locking pin with the under side of the clamp plate sa. l`o gage the width of the space between the jaws when closed, the clamp plate is formed at its front end with a longitudinally disposed slot in which is longitudinally adjustable a spacing stud k2 to enga e the workholding-jaws in front of the fu crum screws a2 and b2 to limit their closing movement.

The details of the operating mechanism can be altered Without departing from anyy of the principles of the invention.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is;

1. In a sewing machine, the combination with stitch-forming mechanism and workholding means, of a thread-severing mechanism comprisinflr relatively movable threadengaging members, automatically acting means for operating said members whereby one of them performs an initial movement. to enter a loop of a. stitch formed by the stitch-forming mechanism, and manually operated means for actuating the other of said members transversely to said initial movement to sever the thread.

2. In a sewing machine, the comliination with stitch-forming mechanism comprising a reciprocating needle and a cooperating loop-taker, of a thread-severing device comprising a slide-plate, a severing member xed thereon and movable therewith adjacent the needle-path, a movable severing member pivotall connected to the slideplate, automaticfily acting means for om. ating the slide-plate to positin the xed and oscillntin severing members in the needle-t-lucadoo i distended by the looptaker in the pro notion of the last stitch of a. group of stitches, and manually operated means to actuatc the oscillating severing member to sever the thread.

3. In a sewing machine, the combination with stitch-forming mechanism comprising a reciprocating needle and complemental lower-thread mechanism,- of a thread-severing device comprising a slide-plate, a severing member fixed thereon and movable therewith adjacent the needle-path, a movable severing member pivotally connected to theslide-plate, automatically acting means for operating the slide-plate to position the fixed und oscillating severing members in the needle-thread loop of the last stitch of a group of stitches, manually operated means to actuate the oscillating severing member to sever the needle-thread, a second pivotally mounted severing member movable diiferentially in respect of the firstnamed pivotally-mounted severing member, and means whereby the second-named severing member is operated to sever the lou-'er thread.

4. In a sewing machine, the combination with stitch-forming mechanism con'iprising a reciprocating needle and complemental ioWer-thread mechanism, of a tlueadse\-'er ing device comprising a slide-plate, a severing member fixed thereon and movable therewith adjacent. the needle-path, a movable severing member pivotally connected to the slide-plate, automatically acting means for operating the slide-plate to position the fixed and oscillating severing members in the. needlc-thread-loop of the last stitch of a group of stitches, manually operated means to actuatc the oscillating severing member to sever the needle-thread, a second ivotally mounted severing member Inova le differentially in respect of the firstnamed pivotally mounted severing member, and a connection intermediate said pivoted severing members ,whereby the secondnamed member is actuated to sever thc lower thread.

5. In a sewing machine, the combination with stitch-forming mechanism comprising a reciprocating needle and complcmental lower-thread mechanism, of a thread severing device comprising a slide-plate, a severmg member fixed thereon and movable therewith adjacent the needle-path, a. movable severing member pivotally connected to the slide-plate, automatically actingmcans for operating thc slide-plate to position the fixed and oscillating severing members in the necdlc-tln'ead-loop of the laststitch of a group of stitches, manually operated means to actnate the oscillatln Severin member to sever the needle-threat a scconc severing member pivotally mounted upon a stationary fulcrum, and an operative connection intermediate said pivotally mounted severing members whereby the actuation of the one 1n severing the needle-thread produces the actuation of the other to sever the lower thread.

6. In a sewing machine, the combination with stitch-forming mechanism comprisin a reciprocating needle and complementa lower-thread mechanism, of a thread-severing device com rising a slide-plate, a severing member xed thereon and movable therewith adjacent the needleath, a movable `severi U member pivotal v' connected tothe slide-p ate, automatically acting means for operating the slide-plate to position the fixed and oscillating severing members in the needle-thread-loop ot the laststitch of a group of stitches, manually operated means to actuate the oscillating severine member to sever the needle-thread, a secon severing member overlying the first-named pivoted severing member and pivotally mounted upon a sta.- tionary fulcrum and provided with a camslot, and a stud carried by the first-named pivoted severing member and intering the cam-slot of the second-named pivoted severing member whereby the latter is operated to sever the lower thread.

7. In a sewing machine, the combination with stitch-forming mechanism com rising a reciprocating thread-carrying neef le and a coperating loop-taker carrying a lower thread, of a thread-severing device comprising a carrier, upper-thread severing members respectively fixedly and movablyr mounted thereon, automatically acting means whereby said severing members are introduced into a needle-thread-loop in the production of the last of a succession of stitches, means for shiftilw the movable severing member laterally for successively Severino the needle-thread-loop and engaging and, drawinv oif the lower thread for a succeeding stithing operation, a lowerthread severing member, and means for actuating the same to sever the lower thread.

8. In a sewing machine, the combination with stitch-forming mechanism com rising a reciprocating thread-carrying nec( le and a coperatir; loo -taker carrying a lower thread, of a threa -severing device comprising a carrier, up r-thread severing members respectively xedlv and movably mounted thereon, automatically acting means whereby said severing members are introduced into a needle-thread-loop in the production of the last of a succession of stitches. means for shiftin the movable severing member laterally or successivelyr Severin the needle-thread-loop and engaging an drawing ntf the lower-thread for a succeeding stitching operation, a lower-thread severing member, and an operative connection between said movable severing member for the needle-thread and the severing member for the lower thread whereby the latter is actuated bv the operative movement of the former in drawing ott` lower thread.

9. In a sewing machine, the combination with stitch-forming mechanism comprising a reciprocatinn' thread-carrying needle and a coperating lnoop-taker carryiu a lower thread, of a thread-severing evice com prlsing a carrier, upper-thread severing members respectively fixedly and movaby mounted t ereon, automatically acting means whereb said severing meinbers are introduc into a needle-threadloop in the production of the last of n succession of stitches, a lower-thread clamping device, means for shifting the movable severing member laterally for snccessively severing the needle-thread-loop and engagin and drawing olf the lower thread and introducing the same into the lower-thread clamp, a lower-thread Severin member adapted to engage the lower threa intermediate said clamp and the work, and means for actuating the same to sever the lower thread.

10. In a sewing machine. the combination with a reciprocating thread-carrying needle and a coperating loop-taker carrying a lower thread, of a. thread-severing device comprising a reciprocating slide-plate, a severing member fixed thereon. a severing member ivotally connected to the slideplate an arranged to normaa'llj1 register therewith, means for actuating the slideplate to position the fixed and pivoted severin members in the needle-thread-loop of the ast stitch of a group, means for actuating the ivoted severing member to strain the need e-thread against the fixed severing lnember and to engage and deflect the lower thread extending from the loop-taker to the work, a second severing member, and means for actuating the second severing member to sever the lower thread while held in a strained condition by the first-named severing member.

11. In a sewing machine, the combination with a reciprocating thread-carrying needle and a cooperating loop-taker carrying a lower thread, and a throat-plate having a. needle-aperture, of a thread-severing device comprising a reciprocating slide-plate having a throat. at the end adjacent the needleaperture of the disent-plate and an upper thread severing inen'iber fixed thereon at one side of said throat., an upper-thread severing member pivotally connected to the slideplate and arranged to normally register with the fixed severing member. a lower-thread severing member movable across the needleaperture in the thwart-plate,- mcans for 1c ating the slide-plate to position the severing members in the 'teedle-thrcad-loop of the last of a. succession of stitches, and means for actuating the pivoted upper-thread and movable lowertln'ead severing members for severing the respective threads.

1Q. In a sewing machine, the combination with a reciprocating thread-carryiug needle and a coperating loop-taker carrying aV lower thread, and a throat-pitite having n needle-aperture, of a thread-severing device comprising a reciprocating slide-pla te having a throat at the end adjacent the needle-aperture of the throat-plate and an upper-thread severing member fixed thereon at one side of said throat, an upper-thread severing member pivotally connected to the slide plate and arranged to normally register with the fixed severing member, a lower-thread severing member fulerumed to the throat` plate, means for automaticallvr actuating the slide-plate to position the upper-thread severing members in the needle-thread-loop of the last stitch of a succession of stitches. and means for actua-ting the pivoted upperthread and movable lower-thread severing members for successively severing the upper and lower threads.

13. In a sewing machine, tbe combination with stitch-forming mechanism comprising a reciprocating thread-carrying needle and a eoperating loop-taker.l a throat-plate having an aperture through which said needle reciprocatcs,a11d a work-ladder. of a. threadse\-'ering device comprising a reciprocating slide-plate disposed beneath the work-holder and having a throat adapted to register with the needle-aperture of the throat-plate, a Severin member fixed upon the slide-plate at the side of the throatand extending in the direction of reciprocation of the slide-plate and ada ted to enter a needle-thread loop distende( by the loo i-talier, an auxiliary severing member Inova. ly mounted upon the slide-plate, and means for actuating said movable member to strain the thread against the fixed severing member and thereby cause the severing of thesame.

14. In a sewing machine, the combination with stitch-forming mechanism comprising a reciprocatin,'rv thread-carrying needle and a coperating loop-taker, a throat-plate having an aperture tl'nough which said needle reciprocates, and a work-ladder, of a threadsevering device comprising a reciprocating slide-Piate disposed beneath the work-holder and having..r a severing member fixed thereto, an oscillating severing member fulcrunied to the slide-plate and normali)r registeril'xg with the fixed severing member, means for actuating the oscillating severing member, a second differentially movable severing member, and a connection intermediate the. movable severing members whereby the opel.'-

'wasn ative movement of one is communicated to the other with an interval between their severing actions.

15. In a sewing machine, the con'nbination with stitch-forming mechanism comprising a reciprocating thread-earrying needle and a coperating loop-taker, a throat-plate having an aperture through which said needle reciprmfates, and a Work-holder, of a threadsevering device comprising a` reciprocating slideplate beneath the work-holder and having a severingr member tixed thereto and provided with a slot, an oscillating severing member ulcrnmed to the slide-plate and normally registering with the fixed severing member, a stud carried b v said oscillating ser ering member and projectingr through the slot in the slide-plate, a second severing member having a slot therein for said stud` whereby the second-named severing member can be actuated by the oscillation ot' the First-named severing member, and means for locking said severing niembers in one extreme. position of the slideplate.

1G. In a sewing machine, the combination with stitch-forming mechanism comprising a reciprocating thread-carrying needle and a coperating loop-taker, a throat-plate having an aperture through which said needle reeiprocates, and a work-holder, of a thread-severing device comprising a reciprocating slide-plate beneath the Work-holder and having a severing member fixed thereto and provided with a slot, an oscillating severing member fulcrumed to the slideplate and normally registering with the xed severingmember, a stud carrled by said oscillating severing member and projecting through the slot in the slidelate, a second severing member having a s ot therein for said stud, whereby the second-named severing member can be actuated by the oscillation of the first-named severing member, and means acting upon said stud and adapted to lock the first-named severing member from movement in one extreme position of the slide-plate.

1T. In a sewing machine, the combination with stitch-forming mechanism comprisi a reciprocating thread-carrying needle :ld acoperating loop-taker, a throat-plate having an aperture through which said needie reciprocates and a cam-groove having a contraction at. one end and an enlargement at the other end. and a. work-holder, of a thread-severing device comprising a reciprocating slide-plate beneath the work-holder and having a severing member fixed thereto and provided with a slot, an oscillating severing member fulcrumedl to the slideplate and normally registering with the fixed severing member, a stud carried by said oscillating severing member and projecting through the slot in the'slide-plate and into said cam-groove of the throatplate, and a second severing member having a slot therein for said stud whereb the second-named severing mem er can actuated by the oscillation of the first-named severing member. l

18. In a sewing machine, the combm'atlon with stitch-form mechanism including a reciprocating need e and a coperatlng looptaker, and a throat-plate having an aperture throu h which said needle reci rocates, and provided adjacent thereto on t le under side-with a pro'ection aording a stationary clamping mem r and an adjacent depression, of a thread-Severin dmeclhenism comr1s1 a reciprocating s 1 e-p a carrying ii pexlthread severing members, a revoluble am ing member having spaced fingers mova le across the needle-aperture for enaging the u per thread and clamping it etween itsel and the stationary clamping member, and means carried by said slideplate for imparting to the revoluble clampmg member step-by-step movements in one direction.

19. In a sewing machine, the combination with stitch-formi G mechanism including a reciprocating need e and a cooperating looptaker, and a throat-plate having an aperture throu which said needle reciprocates and provi ed adjacent thereto on the under side with a projection aIordin astationary clamping member and an a jacent depression, of a thread-Severin mechanism comprismg a reciprocating s ide-plate carrying u per-thread severing members, a. revoluble ing member having spaced fingers movaible across the needle-aperture for engeaging the u per thread and clamping it tween itsel and the stationary clamping member, means for advancing the slideplate to carry said severing members to operative positlon and for retracting the same in two stages of movement, and means carried by said slide-plate for im arting to the revoluble clamping member uring the retraction of the slide-plate atwo-sta e operative movement whereby the needleead is successively clamped upon the stationary clamping member and thereafter released at the ad'acent depression in the throat-plate.

20. 1111 a sewing machine, the combination with stitch-forming mechanism including a reciprocating needle and a coperat-ing looptaker, and a throat-plate having an aperture throu h which said needle reciprocates and proviged adjacent thereto on the under side with a pro'ection affording a stationary clamping mem r and an adjacent depression, of a thread-severing mechanism, a revoluble clam ing member having spaced fingers movab e across the needle-a erture for enga-ging the upper thad an clamping it etween itself and the stationary clamping member, automatically acting means for actuut-ing the revoluble clamping member in two separate sta es to first engage and hold the needle-three for u selected number of stitches and to thereafter release the same, and controlling means for said revolublc member.

21. In a sewing machine, the combination with stitch-formlng mechanism including a reciprocating needle and a coperating looptaker, and a. throat-plate having an aperture through which said needle reciprocates and provided adjacent thereto on the under side with a projection affording a stationary clamping member and an adjacent depression, of a thread-severing mechanism, a revoluble clam ing member having spaced iingers movab e across the needle-aperture for engaging the upper thread and clamping it between itself and the stationary clamping member, automatically and positively acting means for actuating the revoluble clamping member in two separate stages to first engage and hold the needle-thread for a selected number of stitches and to thereafter release the same, and controlling means for imposing a frictional drag upon said revoluble member to prevent both overthrow and retrograde movement of the latter.

,22. An upper thread-clamp for a sewing machine, comprising a throat-plate having an annular recess in the lower side thereof and a needle aperture contiguous to and within the rim of the recess, a clamping member mounted to revolve within therecess and having a series of fingers successivelv and intermittently movable across the need e-aperture, means for intermittently actuating the clamping member consisting of a slid-plate, a spring-pressed detenta-dog carried thereby to successively engage the fingers of the revoluble clamping member, means for actuating the slide-plate to rotate the clamp' member a distance of one tinger across t e needle-aperture on each operation of thc thread-severing means, and to hold it stationair.y so that it will anfrage and hold the upper thread for a selectec number of stitches on the nextoperation of the stitch-forming mechanism, und then actuate it on t-he completion of the selected number of stitches to relase the thread.

23. An upper thread clamp for a sewing machine, comprising a throat-plate havin an annular recess in the lower side thereo and a needle aperture contiguous to and within the rim of the recess` a clamping member mounted to revolve Within the recess and having a series of lingers successively7 and intermittently movable across the need e aperture, means for intermittently actuating the clamping member, consisting of a slide-plate and a spring-pressed detentdog carried thereby to successively engage the fingers of the revolublc clamping member, means for actuating the sli e-plate to rotate theclamping member a distance of -Qne fin l.' acrossthe needle-a ertui'c on each operation of the thread-severing nicnas, and

to hold it stationary so that it will engage and hold the upper thread for 'a selected number of stitches on the next operation of the stitch-forming mechanism, and then actuate it on the completion of the selected number of stitches to release the thread, and

a detent means to frict-ionally engage the clamping member.

24. In a sewing machine, the combination with stitch-forming mechanism including a. reciprocating nee e-bar, of a thread-retailler upon said needle-bar, manually controlled means for actuating the thread-retainer whereby the thread may be clamped revious to the initial descent of the needlear, and means independent of said actuating means for releasing the thread in the initial ascent of the needle-har for each sewing operation.

25. In a sewing machine, the combination with the needle-bar having a thread-groove therein, of a thread-retainer consisting of a,

sleeve rotatably mounted upon the needlebar and having a thread-aperture therethrough re istering with the thread-groove in the nee e-ba: when the thread-retainer is ino erative, and means to position the threa -reta-iner to displace the thread-aperture from alineinent with the thread-groove.

26. In a sewing machine, the combination with the needle-bar having a peri heral thread-groove atits lower end, of a t eadretainer consistin of a sleeve loosely mounter on the needle ar and having a threadaperture to register with the said threadgroove when the thread-retainer is in its ino erative osition, means to yieldingly press t e wall o the sleeve adjacent to the threadaperture against the needle-bar, and means to move the sleeve to position the threadaperture where it will be out of register with the thread-groove.

27. In a sewi machine, the combination with a needlear having a peripheral thread-groove near its lower end, of a thread-retainer consisting of a sleeve loosely 5 mounted upon the needle-bar and having a thread-aperture to register with the said thread-groove when the thread-retainer is ino erative n spring within the sleeve to yie dingl liold the wall of the thread-retainer a jacent to the aperture a Vainst the needle-bar, a projection from the s eeve and actuating means to engage the projection and position the sleeve where its wall can clamp the thread, and other means to autoy 6 matically engage the projection and position the sleeve where it will release the thread.

28. In a sewing machine, the combination with a needle-bar having a peripheral threadgroove nezii' its lower end, of a j thread-retainer consisting of n. sleeve loosely mounted upon the needle-haiand having a thread-aperture to register with the said thread-groove when the thread-retainer is inoperative, a spring within the sleeve to yieldingl hold the wall of the thread-re- 7o taincr a( jacent to the aperture against the needle-bar, a projection from the sleeve, a lifting lever, a reciprocating cani actuated by the lever to engage the projection of the thread-retainer and position the sleeve of 7: the latter on the needle-bar to clamp the thread, and u. stationary cam to enl age the projection of the thread-retainer an restore the sleeve to inoperative position.

29. In a sewing machine7 the combination 30 with the needle-bar, of an up ier-thread retainer mounted thei'eon, a projection for the upper-thread retainer, a slide-bar, a skeleton-cani pivotally connected to the lower bearing of t-he slide-bai', a stud for the slide- 3.5 bai' operating in the skeleton-cam, a reciproeating arm actuated by the skeleton-cam to engage the )rejection of the thread-retainer to position t ie thread-retainer on the needlebar where it will clamp the thread, and a sta- 9o tionary cam connected to the lower bearing of the needle-bar to engage the projection of tliethiead-retainer and restore the latter to its inoperative position.

30. In a sewing machine, the combination g5 with a reciprocating thread-carrying needle and a coperating loop-taker carrying a lower thread, of a stationary thread-clamping member, means for drawing off lower thread and carrying it beneath the threadclampi member and coperating therewith in iolding the thread taut, and an independently actuated member for severing the thread so held.

31. In a sewing machine the combination with a reciprocating thread-carrying needle, and a cooperating loop-taker carrying a lower thread, of an up r-thread severing device including operative members adapted to enter a loop of needle-thread, a lowerthread severing device, an operative conknection between the upper and lower-thread severing devices and common manuallyoperated means for actuating thesame to sever the upper and lower threads, a needlethread clamp independent of the upperthread severing device, and actuating means therefor carried by the latter, and a multithrow cam and connections between the saine and the upper-thread severing device whereby the latter is advanced to enter the needle-thread loop reparatoiy to manual actuation to sever tllie threads2 the upperthread device is thereafter partially retracted and the end of the succeeding needlethread loop is clamped, and said severing device is finally retracted to initial position and the needle-tliread-end finally released.

32. In a sewing machine, the combination with stitch-forming mechanism including 

